The present invention relates generally to agricultural implements and more particularly relates to implements capable of being folded between operational and transport configurations.
Modern drawn and integral implements are wider and heavier than their earlier counterparts as manufacturers attempt to provide implements which will increase farmer productivity and profitability. As implements are increased in size, transport and storage present additional difficulties. To reduce the size of implements during transport and storage, various approaches have recently been utilized including rearwardly and upwardly folding implement frames.
When implement frames are folded rearwardly, it is necessary to prevent the tools mounted at the ends of the adjacent sections from interfering with one another. Consequently, some existing rear fold implements utilize means to elevate the tool-supporting toolbars on all sections prior to folding while others provide wing sections which are rearwardly offset from the center section by an amount equal to the tool support length. In those implements which elevate the working tools, pivotal connections between the toolbars must be structurally strengthened and hydraulically operated linkages increase both manufacturing and maintenance expenses. In those implements wherein the wing sections are rearwardly offset from the center section tool-carrying portion, the tools on the center section operate along a transverse line forwardly spaced of that transverse line along which the outer sections operate. Accordingly, the tools along each line will often penetrate to different levels as undulating ground contours are encountered.
Many existing rearwardly folding implement frames have no powered means to assist in folding, but are folded as the operator slowly advances the implement across the field. To unfold the outer sections in this type of implement, it must be slowly backed up. Oftentimes, the wheels of one outer section will hang up on some small ground obstacle making the folding process time consuming and burdensome.
Some upwardly folding implement frames require structural reinforcement to support the elevated tools and wings and many times encounter high maintenance expenses. Further, upwardly folding sections having wide outer sections often extend too high when folded and prevent transport beneath rural power lines, trees and other similar low-hanging obstacles. Thus, these toolbars are limited as to maximum practical widths.